Conductive metal silicides are commonly used in integrated circuitry fabrication due to their high electrical conductivities. For example, such materials are used as conductive strapping layers over conductively doped polysilicon gate lines. Such materials are also used as contact interfaces for conductive contacts. For instance in many integrated circuits, electrically conductive plugs (for example elemental metals, alloys, metal compounds, or conductively doped semiconductive material) are electrically connected with underlying conductively doped silicon. Conductive metal silicides make excellent conductive interfaces between underlying conductively doped semiconductive material and the same or other conductive material received thereover. However, there are instances where it is desired that conductive metal silicides not be utilized in such contacts, for example where excessive leakage current to underlying substrate material is problematic. Accordingly, in fabricating contacts at a given elevation within a substrate, it is sometimes desirable that silicides be formed in some regions and not in others.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. The invention is only limited by the accompanying claims as literally worded, without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.